From: Tony Li <tli@cisco.com> > The only charging scheme that I can see working is to charge people for > advertising routes, with the charge related to the scope over which the > advertisement is seen. That way, there's a direct relationship between > the amount of resources consumed, and the amount charged A global charging scheme implies that there is a centralized, global charging authority. ... What MAY fly, however, is if individual backbones charge for advertisements as well as bandwidth. Ah, I wasn't clear; I was not proposing that this charging be done through any centralized authority. My mental model was much more like your latter thought; individual ISP's would charge for carrying routes, so it would be distributed and decentralized. There are lots of problems you have to work, through, though (see below). Mind, I'm not saying that I'm positive that charging for routes is a *practical* or *desireable* business strategy (there are clearly all sorts of problems). Some sort of cooperative effort to keep routing table sizes down might be more effective overall (i.e. higher cost/benefit ratio) than charging (which is going to have a lot of administrative overhead). However, we might not be able to make that work, in which case charging is the ultimate fallback; having a feedback loop from consumption of resources (routing table entries) to consumers of them is an industrial-strength approach to solving the problem. This would be charged back through regional ISPs, who would decide which backbones to connect to and charge back to their respective customers. Right, your charge would effecitively be related to the scope over which the advertisment was seen, since more the ISP's that carried it -> a bigger total charge. However, there are lots of niggling little problems you have to work out. Here are a few. ISP's cannot charge a flat price per route, since it's not clear that more $$$ will instantly translate into more route-carrying capacity. Set the $$$/route too low, and people will just pay, and the ISP won't have the capaccity. The fact is they have a limited capacity for routes, so there has to be a price curve to discourage further routes as an ISP nears capacity. This will ensure that route resources get allocated to the people who need them the most -> can make best use of them. Even if ISP's do charge a flat price, on a first-come first-served basis, all that will do is create a seceondary market in routes for that ISP; i.e. windfall profits for some, etc. Better would be a "treasury auction" type system. All this is a lot of work, I know; maybe the ISP will just go the flat price route and stay out of the secondary market. (Of course, that leads to the ability to manipulate; hold back a few routes, wait till the price peaks, and then leak them out onto the market; etc, etc..) Another concerns the cross-charging; i.e. with two large providers it easy, they both carry lots of routes for each other, so probably it's a wash (i.e. no money changes hands when the dust settles). But what about small providers? Ideally, you'd like small providers who are being "good guys" (i.e. generating only a few routes) to also have a wash, and the ones who are "bad guys" (ie.. generating lots of routes) to have to pay for it. In other words, small providers have to charge the large providers something for carrying their routes through a small scope (the small ISP) which balances what the large ISP's will charge for carrying the small ISP's route(s). However, this model breaks down when you get to the level of customers; nobody is going to pay customers for carrying routes! So, there remain some holes to be closed up there too. What I'm leading to with all this is that yes, we could create a very efficient (in the sense of allocating costs accurately) market for carrying routes, but it would be very inefficient (in terms of the amount of overhead B/S). Which goes back to my comment above, that maybe charging for routes does not make sense in a larger business context. However, not charging for routes implies we have to come up with another way of controlling routing table growth. I'd be delighted to have a serious conversation about the pros and cons of various charging schemes. Maybe charging's a loser, maybe it's not, but if we're going to consider it, let's look at it seriously, not discard it offhand as "politically incorrect" for the 'net, or whatever. Noel